diff --git a/lib/dust.js b/lib/dust.js
index 6b66566c..e95c0735 100644
--- a/lib/dust.js
+++ b/lib/dust.js
@@ -200,7 +200,7 @@
     }
 
     for (;fromIndex < length; fromIndex++) {
-      if (this[fromIndex] === item) {
+      if (arr[fromIndex] === item) {
         return fromIndex;
       }
     }
diff --git a/test/core.js b/test/core.js
index 488519a0..9c280c43 100644
--- a/test/core.js
+++ b/test/core.js
@@ -118,6 +118,26 @@ exports.coreSetup = function(suite, auto) {
       unit.fail(err);
     });
   });
+
+  suite.test("indexInArray", function() {
+    var unit = this,
+        arr = ["hello", "world"],
+        nativeIndexOf = Array.prototype.indexOf,
+        indexOf;
+    indexOf = dust.indexInArray(arr, "world");
+    unit.equals(indexOf, 1);
+    indexOf = dust.indexInArray(arr, "foo");
+    unit.equals(indexOf, -1);
+    Array.prototype.indexOf = undefined;
+    // test indexOf when the array indexOf function is undefined (IE lte 8)
+    indexOf = dust.indexInArray(arr, "world");
+    unit.equals(indexOf, 1);
+    indexOf = dust.indexInArray(arr, "foo");
+    unit.equals(indexOf, -1);
+    Array.prototype.indexOf = nativeIndexOf;
+    unit.notEquals(Array.prototype.indexOf, undefined);
+    unit.pass();
+  });
 }
 
 function testRender(unit, source, context, expected, options, baseContext, error, logMessage) {
diff --git a/test/uutest.js b/test/uutest.js
index 97415e46..1d744aa9 100644
--- a/test/uutest.js
+++ b/test/uutest.js
@@ -27,6 +27,14 @@ Test.prototype.equals = function(actual, expected, message) {
     }
 }
 
+Test.prototype.notEquals = function(actual, expected, message) {
+    if (actual === expected) {
+        var err = new Error();
+        if (message) err.message = message;
+        throw wrapAssertionError(err, actual, expected, "===");
+    }
+}
+
 Test.prototype.ifError = function(err) {
   if (err) throw err;
 }